package com.carloha.finance.tool;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 文件下载相关
 * 
 * @author 草原狼
 * @date 2019-7-13
 */
public class HttpUtil {
	static final Logger LOG = LoggerFactory.getLogger(HttpUtil.class);
	public static final String charset = "UTF-8";

	/**
	 * 获取网络输入流
	 */
	public static byte[] getURLInputStream(String urlStr) {
		try {
			URL url = new URL(urlStr);
			HttpURLConnection conn = (HttpURLConnection) url.openConnection();
			// 设置超时间为3秒
			conn.setConnectTimeout(5 * 1000);
			// 防止屏蔽程序抓取而返回403错误
			conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
			// 得到输入流
			InputStream inputStream = conn.getInputStream();
			// 获取自己数组
			byte[] imgb = readInputStream(inputStream);
			return imgb;
		} catch (Exception e) {
			LOG.error(e.getMessage(), e.getCause());
		}
		return null;
	}

	/**
	 * 从输入流中获取字节数组
	 * 
	 * @param inputStream
	 * @return
	 * @throws IOException
	 */
	public static byte[] readInputStream(InputStream inputStream) throws IOException {
		byte[] buffer = new byte[1024];
		int len = 0;
		ByteArrayOutputStream bos = new ByteArrayOutputStream();
		while ((len = inputStream.read(buffer)) != -1) {
			bos.write(buffer, 0, len);
		}
		bos.close();
		return bos.toByteArray();
	}

}
